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-rw-r--r--include/linux/mmzone.h1
-rw-r--r--include/linux/page-flags.h5
-rw-r--r--include/linux/swap.h2
-rw-r--r--include/trace/events/mmflags.h1
-rw-r--r--mm/filemap.c9
-rw-r--r--mm/huge_memory.c1
-rw-r--r--mm/migrate.c2
-rw-r--r--mm/swap_state.c1
-rw-r--r--mm/vmscan.c1
-rw-r--r--mm/vmstat.c1
-rw-r--r--mm/workingset.c95
11 files changed, 77 insertions, 42 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7bbeba21f6a3..ba51d5bf7af1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -163,6 +163,7 @@ enum node_stat_item {
NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
WORKINGSET_REFAULT,
WORKINGSET_ACTIVATE,
+ WORKINGSET_RESTORE,
WORKINGSET_NODERECLAIM,
NR_ANON_MAPPED, /* Mapped anonymous pages */
NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 74bee8cecf4c..4d99504f6496 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -69,13 +69,14 @@
*/
enum pageflags {
PG_locked, /* Page is locked. Don't touch. */
- PG_error,
PG_referenced,
PG_uptodate,
PG_dirty,
PG_lru,
PG_active,
+ PG_workingset,
PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */
+ PG_error,
PG_slab,
PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
PG_arch_1,
@@ -280,6 +281,8 @@ PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD)
PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD)
PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD)
TESTCLEARFLAG(Active, active, PF_HEAD)
+PAGEFLAG(Workingset, workingset, PF_HEAD)
+ TESTCLEARFLAG(Workingset, workingset, PF_HEAD)
__PAGEFLAG(Slab, slab, PF_NO_TAIL)
__PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL)
PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8e2c11e692ba..b93740d72e78 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -296,7 +296,7 @@ struct vma_swap_readahead {
/* linux/mm/workingset.c */
void *workingset_eviction(struct address_space *mapping, struct page *page);
-bool workingset_refault(void *shadow);
+void workingset_refault(struct page *page, void *shadow);
void workingset_activation(struct page *page);
/* Do not use directly, use workingset_lookup_update */
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index a81cffb76d89..a1675d43777e 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -88,6 +88,7 @@
{1UL << PG_dirty, "dirty" }, \
{1UL << PG_lru, "lru" }, \
{1UL << PG_active, "active" }, \
+ {1UL << PG_workingset, "workingset" }, \
{1UL << PG_slab, "slab" }, \
{1UL << PG_owner_priv_1, "owner_priv_1" }, \
{1UL << PG_arch_1, "arch_1" }, \
diff --git a/mm/filemap.c b/mm/filemap.c
index de6fed2a0815..7997adce5a29 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -915,12 +915,9 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
* data from the working set, only to cache data that will
* get overwritten with something else, is a waste of memory.
*/
- if (!(gfp_mask & __GFP_WRITE) &&
- shadow && workingset_refault(shadow)) {
- SetPageActive(page);
- workingset_activation(page);
- } else
- ClearPageActive(page);
+ WARN_ON_ONCE(PageActive(page));
+ if (!(gfp_mask & __GFP_WRITE) && shadow)
+ workingset_refault(page, shadow);
lru_cache_add(page);
}
return ret;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index deed97fba979..8ea1b36bd452 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2369,6 +2369,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
(1L << PG_mlocked) |
(1L << PG_uptodate) |
(1L << PG_active) |
+ (1L << PG_workingset) |
(1L << PG_locked) |
(1L << PG_unevictable) |
(1L << PG_dirty)));
diff --git a/mm/migrate.c b/mm/migrate.c
index 84381b55b2bd..1ea27b343ccd 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -685,6 +685,8 @@ void migrate_page_states(struct page *newpage, struct page *page)
SetPageActive(newpage);
} else if (TestClearPageUnevictable(page))
SetPageUnevictable(newpage);
+ if (PageWorkingset(page))
+ SetPageWorkingset(newpage);
if (PageChecked(page))
SetPageChecked(newpage);
if (PageMappedToDisk(page))
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ecee9c6c4cc1..0d6a7f268d2e 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -448,6 +448,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
/*
* Initiate read into locked page and return.
*/
+ SetPageWorkingset(new_page);
lru_cache_add_anon(new_page);
*new_page_allocated = true;
return new_page;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 961401c46334..87e9fef341d2 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2145,6 +2145,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
}
ClearPageActive(page); /* we are de-activating */
+ SetPageWorkingset(page);
list_add(&page->lru, &l_inactive);
}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 2cec2fa4c8ae..d918f6192d15 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1145,6 +1145,7 @@ const char * const vmstat_text[] = {
"nr_isolated_file",
"workingset_refault",
"workingset_activate",
+ "workingset_restore",
"workingset_nodereclaim",
"nr_anon_pages",
"nr_mapped",
diff --git a/mm/workingset.c b/mm/workingset.c
index 7d5fa0dd2b38..99b7f7c09b13 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -121,7 +121,7 @@
* the only thing eating into inactive list space is active pages.
*
*
- * Activating refaulting pages
+ * Refaulting inactive pages
*
* All that is known about the active list is that the pages have been
* accessed more than once in the past. This means that at any given
@@ -134,6 +134,10 @@
* used less frequently than the refaulting page - or even not used at
* all anymore.
*
+ * That means if inactive cache is refaulting with a suitable refault
+ * distance, we assume the cache workingset is transitioning and put
+ * pressure on the current active list.
+ *
* If this is wrong and demotion kicks in, the pages which are truly
* used more frequently will be reactivated while the less frequently
* used once will be evicted from memory.
@@ -141,6 +145,14 @@
* But if this is right, the stale pages will be pushed out of memory
* and the used pages get to stay in cache.
*
+ * Refaulting active pages
+ *
+ * If on the other hand the refaulting pages have recently been
+ * deactivated, it means that the active list is no longer protecting
+ * actively used cache from reclaim. The cache is NOT transitioning to
+ * a different workingset; the existing workingset is thrashing in the
+ * space allocated to the page cache.
+ *
*
* Implementation
*
@@ -156,8 +168,7 @@
*/
#define EVICTION_SHIFT (RADIX_TREE_EXCEPTIONAL_ENTRY + \
- NODES_SHIFT + \
- MEM_CGROUP_ID_SHIFT)
+ 1 + NODES_SHIFT + MEM_CGROUP_ID_SHIFT)
#define EVICTION_MASK (~0UL >> EVICTION_SHIFT)
/*
@@ -170,23 +181,28 @@
*/
static unsigned int bucket_order __read_mostly;
-static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction)
+static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction,
+ bool workingset)
{
eviction >>= bucket_order;
eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid;
eviction = (eviction << NODES_SHIFT) | pgdat->node_id;
+ eviction = (eviction << 1) | workingset;
eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT);
return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY);
}
static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
- unsigned long *evictionp)
+ unsigned long *evictionp, bool *workingsetp)
{
unsigned long entry = (unsigned long)shadow;
int memcgid, nid;
+ bool workingset;
entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT;
+ workingset = entry & 1;
+ entry >>= 1;
nid = entry & ((1UL << NODES_SHIFT) - 1);
entry >>= NODES_SHIFT;
memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1);
@@ -195,6 +211,7 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
*memcgidp = memcgid;
*pgdat = NODE_DATA(nid);
*evictionp = entry << bucket_order;
+ *workingsetp = workingset;
}
/**
@@ -207,8 +224,8 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
*/
void *workingset_eviction(struct address_space *mapping, struct page *page)
{
- struct mem_cgroup *memcg = page_memcg(page);
struct pglist_data *pgdat = page_pgdat(page);
+ struct mem_cgroup *memcg = page_memcg(page);
int memcgid = mem_cgroup_id(memcg);
unsigned long eviction;
struct lruvec *lruvec;
@@ -220,30 +237,30 @@ void *workingset_eviction(struct address_space *mapping, struct page *page)
lruvec = mem_cgroup_lruvec(pgdat, memcg);
eviction = atomic_long_inc_return(&lruvec->inactive_age);
- return pack_shadow(memcgid, pgdat, eviction);
+ return pack_shadow(memcgid, pgdat, eviction, PageWorkingset(page));
}
/**
* workingset_refault - evaluate the refault of a previously evicted page
+ * @page: the freshly allocated replacement page
* @shadow: shadow entry of the evicted page
*
* Calculates and evaluates the refault distance of the previously
* evicted page in the context of the node it was allocated in.
- *
- * Returns %true if the page should be activated, %false otherwise.
*/
-bool workingset_refault(void *shadow)
+void workingset_refault(struct page *page, void *shadow)
{
unsigned long refault_distance;
+ struct pglist_data *pgdat;
unsigned long active_file;
struct mem_cgroup *memcg;
unsigned long eviction;
struct lruvec *lruvec;
unsigned long refault;
- struct pglist_data *pgdat;
+ bool workingset;
int memcgid;
- unpack_shadow(shadow, &memcgid, &pgdat, &eviction);
+ unpack_shadow(shadow, &memcgid, &pgdat, &eviction, &workingset);
rcu_read_lock();
/*
@@ -263,41 +280,51 @@ bool workingset_refault(void *shadow)
* configurations instead.
*/
memcg = mem_cgroup_from_id(memcgid);
- if (!mem_cgroup_disabled() && !memcg) {
- rcu_read_unlock();
- return false;
- }
+ if (!mem_cgroup_disabled() && !memcg)
+ goto out;
lruvec = mem_cgroup_lruvec(pgdat, memcg);
refault = atomic_long_read(&lruvec->inactive_age);
active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, MAX_NR_ZONES);
/*
- * The unsigned subtraction here gives an accurate distance
- * across inactive_age overflows in most cases.
+ * Calculate the refault distance
*
- * There is a special case: usually, shadow entries have a
- * short lifetime and are either refaulted or reclaimed along
- * with the inode before they get too old. But it is not
- * impossible for the inactive_age to lap a shadow entry in
- * the field, which can then can result in a false small
- * refault distance, leading to a false activation should this
- * old entry actually refault again. However, earlier kernels
- * used to deactivate unconditionally with *every* reclaim
- * invocation for the longest time, so the occasional
- * inappropriate activation leading to pressure on the active
- * list is not a problem.
+ * The unsigned subtraction here gives an accurate distance
+ * across inactive_age overflows in most cases. There is a
+ * special case: usually, shadow entries have a short lifetime
+ * and are either refaulted or reclaimed along with the inode
+ * before they get too old. But it is not impossible for the
+ * inactive_age to lap a shadow entry in the field, which can
+ * then result in a false small refault distance, leading to a
+ * false activation should this old entry actually refault
+ * again. However, earlier kernels used to deactivate
+ * unconditionally with *every* reclaim invocation for the
+ * longest time, so the occasional inappropriate activation
+ * leading to pressure on the active list is not a problem.
*/
refault_distance = (refault - eviction) & EVICTION_MASK;
inc_lruvec_state(lruvec, WORKINGSET_REFAULT);
- if (refault_distance <= active_file) {
- inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE);
- rcu_read_unlock();
- return true;
+ /*
+ * Compare the distance to the existing workingset size. We
+ * don't act on pages that couldn't stay resident even if all
+ * the memory was available to the page cache.
+ */
+ if (refault_distance > active_file)
+ goto out;
+
+ SetPageActive(page);
+ atomic_long_inc(&lruvec->inactive_age);
+ inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE);
+
+ /* Page was active prior to eviction */
+ if (workingset) {
+ SetPageWorkingset(page);
+ inc_lruvec_state(lruvec, WORKINGSET_RESTORE);
}
+out:
rcu_read_unlock();
- return false;
}
/**
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 09:37:09 +0000